This invention is concerned with the emulsification and stabilization of fat in meat-in-sauce, meat-in-gravy and meat filling foods (hereinafter "meat foods") which are heat processed; and more particularly to a method resulting in a meat food having a significant diminution of fat separation after processing.
Of the meat foods which are the subject of this invention, meat-in-sauce foods include such popular foods as chili con carne in its various forms, sloppy joe, spaghetti sauce with meat, and the like. Meat-in-gravy foods are prepared from chunk meat and include popular foods such as beef stew, barbecue beef or pork with sauce, and the like. Meat filling foods include taco filling, enchilada filling and burrito filling.
Each of these meat containing food items are cooked in processing. Some are subsequently canned and heat retorted to produce shelf-stable foods. These may also be frozen in containers such as aluminum trays. Others are customarily cooked and frozen in containers before distribution through the marketing chain to the consumer. Some of these meat-containing foods may be cooked at the point of serving, such as in restaurants and institutions.
Over the years, the manufacturers of these meat foods have had to contend with the major problem resulting from the cooking or heat processing; namely, fat separation. The problem of fat separation on heat processing has a number of deleterious implications.
Fat separation after cooking of these meat foods, whether they are canned or heat retorted or frozen in aluminum trays, results in container filling problems. The hot meat-containing mix with this liquified meat fat is portioned by appropriate devices from a vessel by gravity feed to the desired container. Because of the propensity for liquid fat stratification through upward movement in the supply vessel, even with non-aerating agitation, this results in some non-uniformity in the composition of the container contents, from first filled to last filled. The canned items are then retorted to insure shelf stability. This heat stressing further aggravates the fat separation problem. A prime example is canned chili; the can, when open, has a thick layer of red congealed fat at the top of the food mass.
It is obvious that fat separation in meat foods results in diminished eye appeal because of the high visibility of the fat. Further, the separated fat results in a greasy or oily mouth feel, even when the product is warmed for serving. This is because the fat is not thoroughly redispersed in the product by heating.
Food manufacturers have tried several measures to reduce fat separation in meat-in-sauce, meat-in-gravy and meat filling foods. These measures have not been overly successful and have resulted in minimal product improvement. As one measure in controlling undesirable visible fat in meat foods, producers have skimmed liquified fat from the hot product mixture prior to canning or freezing. This is not a sound practice in that the meat food regulations of the Food Safety and Quality Service of the United States Department of Agriculture require a minimum meat content, part of which is the fat that is associated with the lean portion of the meat. Hence, skimming may result in a product which does not conform to Federal regulations.
Other measures include the use of selected additives. Fat absorbing substances such as oat flakes and flour or potato starch may be incorporated in the mix. These will do only a partial job at levels of addition which do not alter the desirable consistency as perceived by the consumer. This is also true of thickening agents such as corn and wheat starches. Levels which result in measurable reduction of fat separation cause thick consistencies which have an undesirable mushy or grainy mouth feel. Further, these levels of additives adversely influence the flavor. This led the art to try non-food additives such as the finely divided silicious or cellulosic materials as described in U.S. Pat. No. 3,836,685.
Soybean products have also been used to control fat separation in a variety of products. Crude lecithin is a well known emulsifier for water in fat in non-meat products such as margarine. Soy protein has been used in controlling fat in products such as beef patties and frankfurters with acceptable changes in the consistency of the product. For example, it has been long known (U.S. Pat. No. 2,881,076) that soy flour was a fat emulsifier for meat. Textured soy protein also has been used to absorb fat and water during normal hydration processes. Many of these soybean products have been used alone, and none of these soybean products has been thought to provide means whereby fat separation could be controlled in cooked meat foods in an acceptable manner. The art, even when dealing with gravy alone (which is subject to much less heating) went to a cheese whey derivative in U.S. Pat. No. 4,140,810, not using a soy protein even though a small amount of soybean phosphatide was employed.